Java example source code file (Http2Client.java)

This example Java source code file (Http2Client.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

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Java - Java tags/keywords

asciistring, bootstrap, channel, defaultfullhttprequest, fullhttprequest, get, http2clientinitializer, httpresponsehandler, port, ssl, sslcontext, string, threading, threads, url2, url2data

The Http2Client.java Java example source code

/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License, version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package io.netty.example.http2.helloworld.client;

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.http.DefaultFullHttpRequest;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpHeaderValues;
import io.netty.handler.codec.http.HttpScheme;
import io.netty.handler.codec.http2.Http2SecurityUtil;
import io.netty.handler.codec.http2.HttpConversionUtil;
import io.netty.handler.ssl.ApplicationProtocolConfig;
import io.netty.handler.ssl.ApplicationProtocolConfig.Protocol;
import io.netty.handler.ssl.ApplicationProtocolConfig.SelectedListenerFailureBehavior;
import io.netty.handler.ssl.ApplicationProtocolConfig.SelectorFailureBehavior;
import io.netty.handler.ssl.ApplicationProtocolNames;
import io.netty.handler.ssl.OpenSsl;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.SslProvider;
import io.netty.handler.ssl.SupportedCipherSuiteFilter;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
import io.netty.util.AsciiString;
import io.netty.util.CharsetUtil;

import java.util.concurrent.TimeUnit;

import static io.netty.handler.codec.http.HttpMethod.GET;
import static io.netty.handler.codec.http.HttpMethod.POST;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;

/**
 * An HTTP2 client that allows you to send HTTP2 frames to a server. Inbound and outbound frames are
 * logged. When run from the command-line, sends a single HEADERS frame to the server and gets back
 * a "Hello World" response.
 */
public final class Http2Client {

    static final boolean SSL = System.getProperty("ssl") != null;
    static final String HOST = System.getProperty("host", "127.0.0.1");
    static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8443" : "8080"));
    static final String URL = System.getProperty("url", "/whatever");
    static final String URL2 = System.getProperty("url2");
    static final String URL2DATA = System.getProperty("url2data", "test data!");

    public static void main(String[] args) throws Exception {
        // Configure SSL.
        final SslContext sslCtx;
        if (SSL) {
            SslProvider provider = OpenSsl.isAlpnSupported() ? SslProvider.OPENSSL : SslProvider.JDK;
            sslCtx = SslContextBuilder.forClient()
                .sslProvider(provider)
                /* NOTE: the cipher filter may not include all ciphers required by the HTTP/2 specification.
                 * Please refer to the HTTP/2 specification for cipher requirements. */
                .ciphers(Http2SecurityUtil.CIPHERS, SupportedCipherSuiteFilter.INSTANCE)
                .trustManager(InsecureTrustManagerFactory.INSTANCE)
                .applicationProtocolConfig(new ApplicationProtocolConfig(
                    Protocol.ALPN,
                    // NO_ADVERTISE is currently the only mode supported by both OpenSsl and JDK providers.
                    SelectorFailureBehavior.NO_ADVERTISE,
                    // ACCEPT is currently the only mode supported by both OpenSsl and JDK providers.
                    SelectedListenerFailureBehavior.ACCEPT,
                    ApplicationProtocolNames.HTTP_2,
                    ApplicationProtocolNames.HTTP_1_1))
                .build();
        } else {
            sslCtx = null;
        }

        EventLoopGroup workerGroup = new NioEventLoopGroup();
        Http2ClientInitializer initializer = new Http2ClientInitializer(sslCtx, Integer.MAX_VALUE);

        try {
            // Configure the client.
            Bootstrap b = new Bootstrap();
            b.group(workerGroup);
            b.channel(NioSocketChannel.class);
            b.option(ChannelOption.SO_KEEPALIVE, true);
            b.remoteAddress(HOST, PORT);
            b.handler(initializer);

            // Start the client.
            Channel channel = b.connect().syncUninterruptibly().channel();
            System.out.println("Connected to [" + HOST + ':' + PORT + ']');

            // Wait for the HTTP/2 upgrade to occur.
            Http2SettingsHandler http2SettingsHandler = initializer.settingsHandler();
            http2SettingsHandler.awaitSettings(5, TimeUnit.SECONDS);

            HttpResponseHandler responseHandler = initializer.responseHandler();
            int streamId = 3;
            HttpScheme scheme = SSL ? HttpScheme.HTTPS : HttpScheme.HTTP;
            AsciiString hostName = new AsciiString(HOST + ':' + PORT);
            System.err.println("Sending request(s)...");
            if (URL != null) {
                // Create a simple GET request.
                FullHttpRequest request = new DefaultFullHttpRequest(HTTP_1_1, GET, URL);
                request.headers().add(HttpHeaderNames.HOST, hostName);
                request.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), scheme.name());
                request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
                request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.DEFLATE);
                responseHandler.put(streamId, channel.writeAndFlush(request), channel.newPromise());
                streamId += 2;
            }
            if (URL2 != null) {
                // Create a simple POST request with a body.
                FullHttpRequest request = new DefaultFullHttpRequest(HTTP_1_1, POST, URL2,
                                Unpooled.copiedBuffer(URL2DATA.getBytes(CharsetUtil.UTF_8)));
                request.headers().add(HttpHeaderNames.HOST, hostName);
                request.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), scheme.name());
                request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
                request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.DEFLATE);
                responseHandler.put(streamId, channel.writeAndFlush(request), channel.newPromise());
                streamId += 2;
            }
            responseHandler.awaitResponses(5, TimeUnit.SECONDS);
            System.out.println("Finished HTTP/2 request(s)");

            // Wait until the connection is closed.
            channel.close().syncUninterruptibly();
        } finally {
            workerGroup.shutdownGracefully();
        }
    }
}